This document relates to sensors and sensor arrays.
Sensors are devices that receive signals and detect one or more parameters in a received signal from one or more targets of interest. For example, a sensor can be an optical sensor that receives and detects an optical signal for optical imaging, or a radio frequency (RF) sensor that receives and detects a signal at a frequency within the RF spectral band. Some sensors are tunable in frequency and can tune their operating frequency within a spectral range. A sensor can be configured to transmit a signal in addition to receiving a signal and such a sensor is a transceiver.